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Cited by 267Animal Behavior and Welfare StudiesHuman-Animal Interaction StudiesAnimal and Plant Science Education

The visitor effect on zoo animals: implications and opportunities for zoo animal welfare

Open access
Sherwen, Sally L., Hemsworth, Paul H.·2019·Animals
DOI 10.3390/ani9060366PMC PMC6617010
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Abstract

Achieving and maintaining high standards of animal welfare is critical to the success of a modern zoo. Research has shown that an animal’s welfare is highly dependent on how various individual animal factors (e.g., species traits, genetics, temperament and previous experience) interact with environmental features (e.g., social grouping, enclosure design and sensory environment). One prominent feature of the zoo environment is the presence of visitors. Visitor contact can be unpredictable and intense, particularly in terms of auditory and visual interaction. Depending on an animal’s perception of this interaction, visitors can have either negative, neutral or positive impacts on zoo animal behaviour and welfare. This paper reviews the literature on the implications and potential opportunities of human-zoo animal interactions on animal behaviour and welfare, with the aim of stimulating interest, understanding and exploration of this important subject. The literature to date presents a mixed range of findings on the topic. It is possible this variation in the responses of zoo animals to visitors may be due to species-specific differences, the nature and intensity of the visitor interactions, enclosure design, and individual animal characteristics. Analysing these studies and better understanding animal preferences and motivations can provide insight into what animals find negatively and positively reinforcing in terms of visitor contact in a specific zoo setting. This understanding can then be applied to either safeguard welfare in cases where visitors can have a negative impact, or, conversely, it can be applied to highlight opportunities to encourage animal-visitor interaction in situations where animals experience positive emotions associated with visitor interaction.

AI snapshot

Written from the paper’s full text.

TL;DR

This review finds that zoo visitors can have negative, neutral, or positive effects on animal behaviour and welfare, depending on species traits, individual characteristics, and enclosure design. It argues that understanding animal preferences and providing choice/control—especially retreat opportunities—can mitigate negative visitor effects and reveal opportunities for positive human–animal interaction.

Key findings

  • The literature reports mixed visitor effects: negative, neutral, and positive. Most studies conclude negative impacts, but the paper notes this may reflect publication bias and welfare science’s traditional focus on negative states.
  • Negative responses include avoidance, hiding, increased vigilance, aggression, stereotypy, and elevated glucocorticoids. For example, red kangaroos spent 15–50% of time in visitor-directed vigilance versus less than 2% in Kangaroo Island kangaroos, and positioned themselves an average of 4 m further from the visitor pathway.
  • Neutral and positive examples exist: meerkats showed no behavioural difference when visitor intensity was reduced; orangutans preferred to position themselves facing an open visitor window; Gentoo penguins showed greater behavioural diversity and increased pool use with higher visitor numbers; Galapagos giant tortoises preferred keeper interaction over object enrichment.
  • Explanatory factors include species evolutionary traits, individual traits, and enclosure features. In one lemur study, visitor variables accounted for around 20% of behavioural variation, dropping to around 6% after time of day and weather were included as covariates; in Canada lynx, lower glucocorticoid concentrations were associated with larger enclosures and more hiding locations across 45 individuals in 22 zoos.

Methods

  • Narrative literature review of the visitor effect in zoos, synthesizing studies on human–zoo animal interactions and animal welfare, including Hosey’s human–animal relationship model.
  • The review covers four main study approaches: site-specific correlational studies, experimental manipulations of visitor conditions, multi-species comparative studies, and multi-institutional comparisons; metrics include behaviour and physiological stress indicators such as glucocorticoid metabolites.
  • Table A1 summarizes the majority of current visitor-effect studies but is described as not exhaustive; no systematic search protocol or meta-analysis is stated.

Limitations

  • Stated: publication bias may overrepresent negative effects; studies are disproportionately focused on non-human primates (almost half of all studies in Table A1), with no published studies on reptiles, amphibians, or fish; methodology varies widely; correlational studies are confounded by weather, time of year, and husbandry, and animal behaviour may influence visitor numbers rather than the reverse.
  • Stated: close encounter experiences, free-range enclosures, large mixed-species aviaries, and visitor feeding are understudied; Table A1 is not an exhaustive list of studies.
  • Evident: as a narrative review without systematic search or meta-analysis, it cannot quantify overall effect sizes, and many conclusions rest on heterogeneous, mixed-method studies.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.3390/ani9060366

Cites

167 of 167 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

55 of 236 cited sources checked · 38 supported · 0 flagged · accuracy not yet measured

  • Premisecitation

    In poultry, high fear of humans was associated with reduced egg production, growth and product quality.

    “Similarly, in poultry, high fear of humans was associated with reduced egg production, growth and product quality [21].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [21] Waiblinger, 2006, Assessing the human–animal relationship in farmed species: A critical review, Appl. Anim. Behav. Sci. source
  • Premisecitation

    Hosey developed the model based on Hediger's early suggestion that humans could potentially be significant to animals as an enemy, prey, a symbiont, an inanimate part of the environment or as a member of the same species.

    “Hosey [25,30] developed this model based on Hediger’s [33] early suggestion that humans could potentially be significant to animals in one of five ways; as an enemy, prey, a symbiont, an inanimate part of the environment or as a member of the same species.”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites [25] Hosey, 2008, A preliminary model of human–animal relationships in the zoo, Appl. Anim. Behav. Sci. source

      Section 4.1 (page not specified) discusses Hediger’s suggestion that keepers might be perceived as conspecifics and visitors as enemies, and uses that distinction to frame human–animal relationships. But it does not give the claimed five-way list. Section 4.7 instead describes the model as incorporating the human–animal relationship concept developed for farmed animals, with zoo visitors added as a variable. (LLM, conf=0.85)

      Experimental — accuracy not yet measured
    • cites [30] Hosey, 2013, Hediger Revisited: How Do Zoo Animals See Us?, J. Appl. Anim. Welf. Sci. source
    • cites [33] Hediger, H. (1970). Man and Animal in the Zoo, Routledge Kegan Paul.

      Not checked in the free run.

  • Premisecitation

    How an animal perceives human interactions is influenced by the nature of the interaction, previous experience with humans, temperament, motivational state, genetics and species.

    “How an animal perceives human interactions is not only influenced by the nature of the interaction but also by other variables, including previous experience with humans, temperament and motivational state, genetics and species [21,24,25].”
    Quote in the paperNot a substantial claim2 of 3 sources checked
    • cites [21] Waiblinger, 2006, Assessing the human–animal relationship in farmed species: A critical review, Appl. Anim. Behav. Sci. source
    • cites [24] Claxton, 2011, The potential of the human–animal relationship as an environmental enrichment for the welfare of zoo-housed animals, Appl. Anim. Behav. Sci. source
    • cites [25] Hosey, 2008, A preliminary model of human–animal relationships in the zoo, Appl. Anim. Behav. Sci. source

      The Introduction says that an animal’s perception of an interaction depends on its nature, past experience, species, personality and motivational state. Section 4.12 also discusses temperament, but the passages found do not identify genetics as a factor. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
  • Interpretationcitation

    Visitors can have negative, neutral or positive impacts on zoo animal behaviour and welfare.

    “Decades of research on the visitor effect in zoos has demonstrated that visitors can have negative, neutral or positive impacts on zoo animal behaviour and welfare.”
    • Also stated in: § Abstract · plain
      “Depending on an animal’s perception of this interaction, visitors can have either negative, neutral or positive impacts on zoo animal behaviour and welfare.”
    Quote in the paperSubstantial claim1 of 5 sources checked
    • cites [12] Blaney, 2004, The influence of a camouflage net barrier on the behaviour, welfare and public perceptions of zoo-housed gorillas, Anim. Welf. source

      The Introduction says visitors may be a source of stress, and Animal welfare implications links their presence to aggression and stereotypic behaviour in the gorillas. The Introduction also describes visitor stimulation as potentially enriching, but the paper does not establish positive welfare effects or a neutral visitor effect; its finding that the barrier had little effect on most behaviours is not the same claim. Page numbers are unavailable in our copy. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
    • cites [13] Davis, 2005, Evidence that zoo visitors influence HPA activity in spider monkeys (Ateles geoffroyii rufiventris), Appl. Anim. Behav. Sci. source
    • cites [14] Sherwen, 2014, A multi-enclosure study investigating the behavioural response of meerkats to zoo visitors, Appl. Anim. Behav. Sci. source
    • cites [15] Margulis, 2003, Effect of felid activity on zoo visitor interest, Zoo Biol. source
    • cites [16] Bloomfield, 2015, Effect of partial covering of the visitor viewing area window on positioning and orientation of zoo orangutans: A preference test, Zoo Biol. source
    • Rests on an assumption: Visitors are a prominent feature of the zoo animal's environment, with frequent, and at times close and intense, interactions.
  • Premisecitation

    Advancements in scientific understanding of sentience and emotions in many species likely drove ethical reflection and raised questions about the quality of life of wild animals in zoos.

    “It is likely that the considerable advancements in our scientific understanding of sentience in many species, and their capacity to experience a suite of emotions [7,8], has driven this ethical reflection and raised questions around the quality of life some wild animals experience in zoos and whether their needs can be met to an acceptable standard [7].”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites [7] Mellor, 2015, Extending the ’Five Domains’ model for animal welfare assessment to incorporate positive welfare states, Anim. Welf. source
    • cites [8] Walker, 2014, Animal welfare science: Recent publication trends and future research priorities, Int. J. Comp. Psychol. source

      The opening discussion (page unavailable) links beliefs about animal feelings to welfare concern, while ‘Research to Assess and Improve the Welfare of Wild and Pet Animals’ (page unavailable) questions whether zoos meet different species’ needs. The paper does not say that advances in scientific understanding drove this reflection; it says some welfare decisions were driven by public pressure rather than scientific insights and stresses that evidence of sentience remains uncertain. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
  • Classified as probably not a substantial claim. 60
  • May combine two claims. 53
  • The quote only partly states this claim. 1

  • Classified as probably not a substantial claim.

    Premisecitation

    The model suggests that Human-Animal Relationships in zoos can be characterised as negative, neutral or positive.

    “This model suggests that HARs in zoos can be characterised in three ways: (i) a negative relationship, where the animal is highly fearful of humans and shows avoidance, (ii) a neutral relationship, if interactions with humans have no consequences for the animal and can lead to habituation to humans, or (iii) a positive relationship, where the animal will potentially experience positive emotions”
    Quote in the paperSubstantial claim1 of 3 sources checked
    • cites [24] Claxton, 2011, The potential of the human–animal relationship as an environmental enrichment for the welfare of zoo-housed animals, Appl. Anim. Behav. Sci. source
    • cites [25] Hosey, 2008, A preliminary model of human–animal relationships in the zoo, Appl. Anim. Behav. Sci. source
    • cites [30] Hosey, 2013, Hediger Revisited: How Do Zoo Animals See Us?, J. Appl. Anim. Welf. Sci. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    A model of the Human-Animal Relationship for the zoo setting was proposed by Hosey, refined and updated in 2013, and presented by Ward and Sherwen.

    “A model of the HAR for the zoo setting was proposed by Hosey [25], then refined and updated in 2013 [30] and presented by Ward and Sherwen [32].”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites [25] Hosey, 2008, A preliminary model of human–animal relationships in the zoo, Appl. Anim. Behav. Sci. source
    • cites [30] Hosey, 2013, Hediger Revisited: How Do Zoo Animals See Us?, J. Appl. Anim. Welf. Sci. source
    • cites [32] Hosey, G., and Melfi, V. (2018). Zoo animals. Anthrozoology: Human-Animal Interactions in Domesticated and Wild Animals, Oxford University Press. source

  • May combine two claims.

    Premisecitation

    Chimpanzees given an additional 10 min a day of positive interaction with a familiar caretaker groomed each other more and displayed lower levels of abnormal behaviour.

    “One study on chimpanzees showed that an additional 10 min a day of positive interaction with a familiar caretaker resulted in chimpanzees grooming each other more and displaying lower levels of abnormal behaviour [27].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [27] Baker, 2004, benefits of positive human interaction for socially-housed chimpanzees, Anim. Welf. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationcitation

    Public scrutiny of zoo animal welfare may intensify as scientific understanding of animal welfare develops further.

    “As such, this scrutiny may be expected to intensify as our scientific understanding of animal welfare develops further [8].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [8] Walker, 2014, Animal welfare science: Recent publication trends and future research priorities, Int. J. Comp. Psychol. source

      In “Research to Assess and Improve the Welfare of Wild and Pet Animals” (page unavailable), the paper notes public attention to some zoo species and predicts more zoo-animal welfare research. It does not predict that public scrutiny will intensify as scientific understanding develops; that connection is not supported by the cited passage. (LLM, conf=0.78)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Ward and colleagues summarise recent advancements in applied animal welfare science in zoos, highlighting five themes including human-animal interactions, anticipatory behaviour, cognitive enrichment, behavioural-biology based husbandry, and reproductive and population management.

    “Ward and colleagues [10] summarise the various recent advancements in applied animal welfare science in zoos, highlighting five themes in particular that have experienced expansion including (a) human–animal interactions, (b) anticipatory behaviour, (c) cognitive enrichment, (d) behavioural-biology based husbandry and (e) reproductive and population management.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [10] Ward, 2018, Advances in Applied Zoo Animal Welfare Science, J. Appl. Anim. Welf. Sci. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The science of animal welfare attempts to make inferences about how animals feel based on welfare indicators such as behaviour, endocrine function and physical health.

    “This field of science attempts to make inferences about how animals feel based on a number of welfare indicators such as behaviour, endocrine function and physical health [10].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [10] Ward, 2018, Advances in Applied Zoo Animal Welfare Science, J. Appl. Anim. Welf. Sci. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The zoo industry has demonstrated significant intensification of zoo-based welfare science.

    “In recent years, the zoo industry has demonstrated significant intensification of zoo-based welfare science, with research being published on a wide range of topics [9,11].”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites [9] Maple, 2018, Introduction: The science and practice of optimal animal welfare, Behav. Process. source

      The Introduction (page not provided) describes seven welfare papers covering varied species and situations, supporting the breadth of research topics. It does not establish that zoo-based welfare science has intensified significantly in recent years across the zoo industry; the authors instead express hope for a research renaissance. (LLM, conf=0.83)

      Experimental — accuracy not yet measured
    • cites [11] Kaufman, A., Bashaw, M., and Maple, T. (2019). Does Research Have a Place in the Zoological Garden?. Scientific Foundations of Zoos and Aquariums: Their Role in Conservation and Research, Cambridge University Press. source

  • May combine two claims.

    Premisecitation

    Research on keeper-animal interactions in zoos has received very little attention, with only a few studies attempting to evaluate this relationship.

    “In comparison to the research that has been conducted in the domestic animal industries, research on keeper–animal interactions in zoos has received very little attention [34], with only a few studies attempting to evaluate this relationship [35,36,37,38,39,40].”
    Quote in the paperNot a substantial claim2 of 7 sources checked
    • cites [34] Carlstead, 2009, A comparative approach to the study of Keeper-Animal Relationships in the zoo, Zoo Biol. source
    • cites [35] Carlstead, 1991, Husbandry of the Fennec fox: Fennecus zerda: Environmental conditions influencing stereotypic behaviour, Int. Zoo Yearb. source
    • cites [36] Chelluri, 2013, Behavioral correlates and welfare implications of informal interactions between caretakers and zoo-housed chimpanzees and gorillas, Appl. Anim. Behav. Sci. source
    • cites [37] Carrasco, 2009, Benefits of training/playing therapy in a group of captive lowland gorillas (Gorilla gorilla gorilla), Anim. Welf. source
    • cites [38] Ward, S.J., and Melfi, V. (2015). Keeper-Animal Interactions: Differences between the Behaviour of Zoo Animals Affect Stockmanship. PLoS ONE, 10. source
    • cites [39] Mellen, 1991, Factors influencing reproductive success in small captive exotic felids (Felis spp.): A multiple regression analysis, Zoo Biol. source
    • cites [40] Wielebnowski, 2002, Noninvasive assessment of adrenal activity associated with husbandry and behavioral factors in the North American clouded leopard population, Zoo Biol. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The study of human impacts on animal welfare in captive settings first arose in the production animal industry in the late 1970s when studies showed wide variation in basic welfare outcomes even when animals were kept in similar physical environments.

    “The study of human impacts on animal welfare in captive settings first arose in the production animal industry in the late 1970s when numerous studies showed wide variation in basic welfare outcomes, even when animals were kept in similar physical environments [17].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [17] Cole, 2018, Zoo Animal Welfare: The Human Dimension, J. Appl. Anim. Welf. Sci. source

      Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

      Experimental — accuracy not yet measured

  • May combine two claims.

    Premisecitation

    The literature on the effects of visitor interactions on zoo animals is ambiguous, with studies providing evidence for negative, neutral and positive impacts.

    “However, the literature on the effects of visitor interactions on zoo animals is somewhat ambiguous, with studies providing evidence for a range of impacts interpreted as negative [12,13], neutral [14,15] and positive [16].”
    Quote in the paperSubstantial claim1 of 5 sources checked
    • cites [12] Blaney, 2004, The influence of a camouflage net barrier on the behaviour, welfare and public perceptions of zoo-housed gorillas, Anim. Welf. source
    • cites [13] Davis, 2005, Evidence that zoo visitors influence HPA activity in spider monkeys (Ateles geoffroyii rufiventris), Appl. Anim. Behav. Sci. source
    • cites [14] Sherwen, 2014, A multi-enclosure study investigating the behavioural response of meerkats to zoo visitors, Appl. Anim. Behav. Sci. source
    • cites [15] Margulis, 2003, Effect of felid activity on zoo visitor interest, Zoo Biol. source
    • cites [16] Bloomfield, 2015, Effect of partial covering of the visitor viewing area window on positioning and orientation of zoo orangutans: A preference test, Zoo Biol. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Common examples of stereotypies include self-scratching or self-mutilatory behaviour in primates, pacing in carnivores, and oral stereotypies such as non-food object licking in ungulates.

    “However, some common examples include self-scratching or self-mutilatory behaviour in primates [54,55,56], pacing in carnivores [57] and oral stereotypies, such as non-food object licking in ungulates [58].”
    Quote in the paperNot a substantial claim1 of 5 sources checked
    • cites [54] Carder, 2008, Visitor effects on anxiety in two captive groups of western lowland gorillas, Appl. Anim. Behav. Sci. source
    • cites [55] Cooke, 2007, Behavioral responses to the zoo environment by white handed gibbons, Appl. Anim. Behav. Sci. source
    • cites [56] Hosey, 2007, Self-injurious Behavior in Zoo Primates, Int. J. Primatol. source
    • cites [57] Clubb, 2003, Animal welfare: Captivity effects on wide-ranging carnivores, Nature source
    • cites [58] Mason, G., and Rushen, J. (2006). Stereotypic Oral Behaviour in Captive Ungulates: Foraging, Diet and Gastrointestinal Function. Stereotypic Animal Behaviour: Fundamentals and Applications to Welfare, CABI Publishing. source

  • May combine two claims.

    Premisecitation

    Visitor variables accounted for around 20% of the behavioural variation observed in lemurs, but this dropped to around 6% after time of day and weather were included as covariates in the model.

    “Their results suggested visitor variables accounted for around 20% of the behavioural variation observed in lemurs, but this dropped to around 6% after time of day and weather were included as covariates in the model [72].”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [72] Goodenough, 2019, Are “visitor effects” overestimated? Behaviour in captive lemurs is mainly driven by co-variation with time and weather, J. Zoo Aquar. Res. source

      The full behavioural models section (p. 8) reports that visitor variables explained about 20% of variation in alertness in a univariate model, falling to about 8% after weather was included. It reports smaller visitor effects of about 3–8% for individual behaviours after accounting for time and/or weather. The claim captures the reduction but presents the alertness-specific 20% as a general result and gives about 6% rather than the reported 8% for that comparison. (LLM, conf=0.86)

      Experimental — accuracy not yet measured

  • Classified as probably not a substantial claim.

    Premisecitation

    Goodenough and colleagues suggest that visitor effects may have been overestimated because of confounding variables associated with variation in visitor numbers.

    “Goodenough and colleagues [72] suggest that visitor effects may have been overestimated for this very reason.”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [72] Goodenough, 2019, Are “visitor effects” overestimated? Behaviour in captive lemurs is mainly driven by co-variation with time and weather, J. Zoo Aquar. Res. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Hosey described the term 'visitor effect' in reference to the study on the impacts of zoo visitors, with systematic investigations largely beginning in the late 1980s and 1990s and growing over time.

    “Hosey [44] described the term ‘visitor effect’ in reference to the study on the impacts of zoo visitors on animals, with systematic investigations into this topic largely beginning in the late 1980s and 1990s and growing over time.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [44] Hosey, 2000, Zoo animals and their human audiences: What is the visitor effect?, Anim. Welf. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Differences were found in the latency of black rhinoceros and Chapman's zebras to appropriately respond to behavioural cues for different keepers, concluding that unique dyads were formed between keepers and these animals.

    “Ward and Melfi [38] found differences in the latency of black rhinoceros and Chapman’s zebras to appropriately respond to behavioural cues for different keepers, concluding that unique dyads were formed between keepers and these animals.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [38] Ward, S.J., and Melfi, V. (2015). Keeper-Animal Interactions: Differences between the Behaviour of Zoo Animals Affect Stockmanship. PLoS ONE, 10. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    It may be that animal behaviour is influencing visitor numbers at enclosures, rather than visitors influencing animals.

    “It is also worthy to note that it may actually be the case that animal behaviour is influencing visitor numbers at enclosures, rather than visitors influencing animals [15,44,73].”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites [15] Margulis, 2003, Effect of felid activity on zoo visitor interest, Zoo Biol. source
    • cites [44] Hosey, 2000, Zoo animals and their human audiences: What is the visitor effect?, Anim. Welf. source
    • cites [73] Mitchell, 1991, Effects of visitors and cage changes on the behaviors of mangabeys, Zoo Biol. source

  • May combine two claims.

    Premisecitation

    Gorillas who underwent training and play sessions with keepers showed lower rates of abnormal behaviour and higher levels of affiliative and intraspecies play behaviour.

    “Carrasco et al. [37]. found that gorillas who underwent training and play sessions with keepers showed lower rates of abnormal behaviour and higher levels of affiliative and intraspecies play behaviour.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [37] Carrasco, 2009, Benefits of training/playing therapy in a group of captive lowland gorillas (Gorilla gorilla gorilla), Anim. Welf. source

  • May combine two claims.

    Premisecitation

    Many species breed successfully and have longevity records greater than their wild counterparts, whereas others fare worse than expected with poorer longevity in zoos than in the wild and show susceptibility to 'stress related illnesses'.

    “Many species breed successfully and have longevity records greater than their wild counterparts, whereas others fare worse than expected with poorer longevity in zoos than in the wild and show susceptibility to ‘stress related illnesses’ [113].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [113] Mason, 2010, Species differences in responses to captivity: Stress, welfare and the comparative method, Trends Ecol. Evol. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Some authors have suggested that temperament traits can be heritable and linked to fitness, making them subject to selection pressure in captivity.

    “Some authors have suggested that temperament traits can be heritable and linked to fitness, making them subject to selection pressure in captivity [129].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [129] McDougall, 2006, Wildlife conservation and animal temperament: Causes and consequences of evolutionary change for captive, reintroduced, and wild populations, Anim. Conserv. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Blaney and Wells suggested that visitor behaviour varied markedly between the two conditions with the camouflage net encouraging quieter, more relaxed visitor behaviours, including less time banging on the glass.

    “they also suggested that visitor behaviour varied markedly between the two conditions with the camouflage net encouraging quieter, more relaxed visitor behaviours, including less time banging on the glass.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [12] Blaney, 2004, The influence of a camouflage net barrier on the behaviour, welfare and public perceptions of zoo-housed gorillas, Anim. Welf. source

  • May combine two claims.

    Premisecitation

    Human-only rearing of zoo animals is associated with abnormal behaviour and reproductive problems.

    “various studies have suggested human-only rearing of zoo animals is associated with abnormal behaviour [81] and reproductive problems [135].”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites [81] Pirovino, 2011, Fecal Glucocorticoid Measurements and Their Relation to Rearing, Behavior, and Environmental Factors in the Population of Pileated Gibbons (Hylobates pileatus) Held in European Zoos, Int. J. Primatol. source

      Citation [135] is attached to reproductive problems, not abnormal behaviour. In the Discussion (page unavailable), the paper reports higher glucocorticoid levels in unnaturally reared pileated gibbons and raises a potential effect on reproduction, but it does not establish reproductive problems specifically associated with human-only rearing. Its rearing category is broader than human-only rearing. (LLM, conf=0.83)

      Experimental — accuracy not yet measured
    • cites [135] Mellen, 1992, Effects of early rearing experience on subsequent adult sexual behavior using domestic cats (Felis catus) as a model for exotic small felids, Zoo Biol. source

  • May combine two claims.

    Premisecitation

    Ross and colleagues found that people who were shown images of chimpanzees in the presence of humans were more likely to believe that wild populations of chimps are stable and would consider owning one as a pet, compared to people who were shown images of chimps without a human present.

    “Ross and colleagues [152] found that people who were shown images of chimpanzees in the presence of humans were more likely to believe that wild populations of chimps are stable and would consider owning one as a pet, compared to people who were shown images of chimps without a human present.”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [152] Ross, S.R., Vreeman, V.M., and Lonsdorf, E.V. (2011). Specific Image Characteristics Influence Attitudes about Chimpanzee Conservation and Use as Pets. PLoS ONE, 6. source

      The Results report that respondents shown a chimpanzee beside a human were less likely to classify wild populations as endangered or declining and more likely to find a chimpanzee appealing as a pet than respondents shown one alone. The pet question measured appeal, not whether respondents would consider owning a chimpanzee, so that part of the claim overstates the finding. (LLM, conf=0.87)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Blaney and Wells reported that visitors tended to speak less and more quietly when the net was in place.

    “They also reported that visitors tended to speak less and more quietly when the net was in place.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [12] Blaney, 2004, The influence of a camouflage net barrier on the behaviour, welfare and public perceptions of zoo-housed gorillas, Anim. Welf. source

  • May combine two claims.

    Premisecitation

    Hand-reared parrots were found to be more likely to suffer from abnormal repetitive behaviours and were more averse to interacting with humans and enrichment compared to naturally-reared birds.

    “hand-reared parrots were found to be more likely to suffer from abnormal repetitive behaviours and were more averse to interacting with humans and enrichment compared to naturally-reared birds [136].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [136] Williams, 2017, The effect of auditory enrichment, rearing method and social environment on the behavior of zoo-housed psittacines (Aves: Psittaciformes); implications for welfare, Appl. Anim. Behav. Sci. source

      The Results (section 2.1.2) and Discussion (section 4.1.4) report more stereotypic behaviour and less interaction with enrichment in hand-reared than parent-reared birds. They do not report greater aversion to interacting with humans; the Introduction (section 1.1) instead says hand-reared birds often prefer human contact over contact with other parrots. (LLM, conf=0.90)

      Experimental — accuracy not yet measured

  • May combine two claims.

    Premisecitation

    Both studies on free range enclosures found behavioural differences in response to different visitor conditions, with increasing visitor numbers resulting in increased time spent vigilant towards visitors in red kangaroos and Kangaroo Island kangaroos, and the presence of visitors resulting in fewer quokkas visible in their enclosure.

    “Both these studies found behavioural differences in response to different visitor conditions, with increasing visitor numbers, resulting in increased time spent vigilant towards visitors in red kangaroos and Kangaroo Island kangaroos [86], and the presence of visitors resulted in fewer quokkas visible in their enclosure [76].”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites [86] Sherwen, 2015, Impacts of visitor number on Kangaroos housed in free-range exhibits, Zoo Biol. source
    • cites [76] Learmonth, 2018, The effects of zoo visitors on Quokka (Setonix brachyurus) avoidance behavior in a walk-through exhibit, Zoo Biol. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingreasoning

    Little attention has been directed towards understanding the effect of temperament traits on an animal's response to visitors.

    “it is surprising that little attention has been directed towards understanding the effect of temperament traits on an animal’s response to visitors.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingnone given

    The effects of visitor interactions on zoo animals are inconsistent; some interactions may be stressful, innocuous or possibly enriching.

    “Clearly the effects of visitor interactions on zoo animals are inconsistent. Some interactions may be stressful, innocuous or possibly enriching for animals.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Findingnone given

    Very little work has been done on identifying species traits that may make them more or less susceptible to negative effects from visitors.

    “Overall, aside from the studies mentioned above, very little work has been done on identifying species traits that may make them more or less susceptible to negative effects from visitors.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Findingnone given

    Large, mixed species bird aviaries are another housing type typically characterised by free-ranging animals and a lack of physical barriers between people and animals, and have been overlooked in the scientific literature.

    “Large, mixed species bird aviaries are another housing type typically characterised by free-ranging animals and a lack of physical barriers between people and animals. Such enclosures have also been overlooked in the scientific literature.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingreasoning

    The impact of participation in close encounter experiences on visitor perception and conservation attitudes remains largely unknown.

    “the impact of participation in these encounter experiences on visitor perception and conservation attitudes remains largely unknown.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Findingnone given

    Housing animals in free range enclosures is an emerging trend that currently lacks sufficient scientific evaluation.

    “Similarly, the housing of animals in free range enclosures also appears to be an emerging trend that currently lacks sufficient scientific evaluation.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Findingnone given

    To the author's knowledge, there are no studies published on the impact of visitors on reptiles, amphibians or fish.

    “to the author’s knowledge, there are no studies published for example on the impact of visitors on reptiles, amphibians or fish”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    At dairy farms where milk yield was low, cows showed greater fear of humans as measured by human approach tests.

    “For example, Breuer et al. [20] found that at dairy farms where milk yield was low, cows showed greater fear of humans, as measured by human approach tests.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] Breuer, 2000, Behavioural response to humans and the productivity of commercial dairy cows, Appl. Anim. Behav. Sci. source

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    The literature to date presents a mixed range of findings on the visitor effect.

    “The literature to date presents a mixed range of findings on the topic.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Researchers have suggested that all species have some natural fear of humans and are likely to perceive them as potential predators, at least in their first interaction.

    “Focusing on fear of humans as a key determinant of the direction of the HAR, researchers have suggested that all species have some natural fear of humans and are likely to perceive them as potential predators, at least in their first interaction [29].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [29] Geffroy, 2015, How Nature-Based Tourism Might Increase Prey Vulnerability to Predators, Trends Ecol. Evol. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Gorillas and chimpanzees showed less self-directed behaviour but more agonistic behaviour in unstructured sessions consisting of one or more positive keeper interactions.

    “For example, Chelluri et al. [36] found that gorillas and chimpanzees showed less self-directed behaviour but more agonistic behaviour in unstructured sessions consisting of one or more positive keeper interactions.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [36] Chelluri, 2013, Behavioral correlates and welfare implications of informal interactions between caretakers and zoo-housed chimpanzees and gorillas, Appl. Anim. Behav. Sci. source

  • May combine two claims.

    Premisecitation

    Human interactions such as hitting, shouting, rough handling, sudden movements and loud noises can be perceived as negative by animals and increase fear of humans.

    “Research showed that human interactions such as hitting, shouting, rough handling, sudden movements and loud noises can be perceived as negative by the animals and, therefore, increase fear of humans [19].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [19] Hemsworth, 2003, Human–animal interactions in livestock production, Appl. Anim. Behav. Sci. source

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Interpretationreasoning

    Variation in zoo animals' responses to visitors may be due to species-specific differences, the nature and intensity of visitor interactions, enclosure design, and individual animal characteristics.

    “It is possible this variation in the responses of zoo animals to visitors may be due to species-specific differences, the nature and intensity of the visitor interactions, enclosure design, and individual animal characteristics.”
    • Also stated in: § 1.1. Zoo Animal Welfare · hedged
      “This variation in the responses of zoo animals to visitors may be due to species-specific differences, the nature and intensity of the visitor interactions, differences in the physical features of enclosures, and individual animal characteristics (e.g., past experiences and temperament).”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: An animal's welfare is highly dependent on how various individual animal factors interact with environmental features.

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    Analysing visitor effect studies and better understanding animal preferences and motivations can provide insight into what animals find negatively and positively reinforcing in a specific zoo setting.

    “Analysing these studies and better understanding animal preferences and motivations can provide insight into what animals find negatively and positively reinforcing in terms of visitor contact in a specific zoo setting.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    There is a growing public expectation that high standards of welfare in all animal-based industries should be achieved and maintained.

    “There is a growing public expectation that high standards of welfare in all animal-based industries should be achieved and maintained [6].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [6] Whitham, 2013, New directions for zoo animal welfare science, Appl. Anim. Behav. Sci. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    A social movement has led to increased public concern and interest in the welfare of animals in captivity.

    “Although personal and community views vary worldwide, it is well recognized that there is a social movement emerging that has led to increased public concern and interest in the welfare of animals in captivity [1,2,3,4,5].”
    Quote in the paperNot a substantial claim0 of 5 sources checked
    • cites [1] Broom, 2016, Considering animals’ feelings: Précis of Sentience and animal welfare, Anim. Sentience Interdiscip. J. Anim. Feel. source
    • cites [2] Gracia, 2013, The determinants of the intention to purchase animal welfare-friendly meat products in Spain, Anim. Welf. source
    • cites [3] Phillips, 2012, Students’ attitudes to animal welfare and rights in Europe and Asia, Anim. Welf. source
    • cites [4] Prickett, 2010, Consumer preferences for farm animal welfare: Results from a telephone survey of US households, Anim. Welf. source
    • cites [5] Vanhonacker, 2008, Do citizens and farmers interpret the concept of farm animal welfare differently?, Livest. Sci. source

  • May combine two claims.

    Interpretationreasoning

    It is possible that human interaction will have an impact on zoo animal welfare because zoo animals are regularly exposed to both familiar and unfamiliar humans in their environment.

    “Nonetheless, it is clear that zoo animals are regularly exposed to both familiar and unfamiliar humans in their environment, and, as such, it is possible that this human interaction will have an impact on their welfare.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Zoo animals are regularly exposed to both familiar and unfamiliar humans in their environment.

  • May combine two claims.

    Premisecitation

    Domestic animals have adapted to humans and the captive environment through genetic changes over generations and environmentally-induced developmental events reoccurring for each generation.

    “Domestic animals have adapted to humans and the captive environment through genetic changes over generations and environmentally-induced developmental events reoccurring for each generation [31].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [31] Price, E.O. (2002). Animal Domestication and Behavior, CAB International. source

  • May combine two claims.

    Premisecitation

    Human-Animal Relationship research in livestock has demonstrated that the relationship is based on the history of interactions between the human and animal, and each partner's experience allows it to learn and anticipate future interactions.

    “Most of this research has been conducted in the livestock industry and has demonstrated that HAR is based on the history of interactions between the human and animal, and each individual partner’s experience of the relationship allows it to learn and to anticipate future interactions and as a result, behave accordingly [18].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [18] Appleby, M.C., Olsson, I.A.S., and Galindo, F. (2018). Human contact. Animal Welfare, CAB International. [3rd ed.]. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    If humans are perceived as a symbiont, this could potentially be a source of enrichment and produce positive welfare outcomes.

    “However, if humans are perceived as a symbiont, this could potentially be a source of enrichment and produce positive welfare outcomes.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Stroking animals in a similar manner to intraspecific allogrooming reduces heart rate and results in relaxed body postures in cattle and lambs.

    “For example, studies have also demonstrated that stroking animals in a similar manner to intraspecific allogrooming reduces heart rate and results in relaxed body postures in cattle [22] and lambs [23].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [22] Schmied, 2008, Stroking of different body regions by a human: Effects on behaviour and heart rate of dairy cows, Appl. Anim. Behav. Sci. source
    • cites [23] Tallet, 2005, Human contact and feeding as rewards for the lamb’s affinity to their stockperson, Appl. Anim. Behav. Sci. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    A negative correlation was found between body size and the level of activity in the primates, but the trend was not statistically significant.

    “They found a negative correlation between body size and the level of activity in the primates. However, the trend was not statistically significant.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [75] Chamove, 1988, Visitors excite primates in zoos, Zoo Biol. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    Increases in vigilance behaviour in zoo animals in response to increasing visitor numbers could reflect interest in visitors and may therefore be considered stimulating for animals.

    “For example, increases in vigilance behaviour in zoo animals in response to increasing visitor numbers could reflect interest in visitors, and may therefore be considered stimulating for animals.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Multi-institutional studies typically are not designed to focus on visitor effects, but they have highlighted significant relationships between animal welfare measures and exposure to visitors.

    “These studies typically are not designed to focus on visitor effects, but they have highlighted significant relationships between animal welfare measures and exposure to visitors.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Chamove and Hosey investigated relationships between the body size of 12 species of primates and their responses to visitors, based on the hypothesis that small species may be particularly prone to effects from visitors.

    “For example, Chamove and Hosey [75] investigated the relationships between the body size of 12 species of primates and their responses to visitors, based on the hypothesis that small species may be particularly prone to effects from visitors.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [75] Chamove, 1988, Visitors excite primates in zoos, Zoo Biol. source

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Premisecitation

    To analyse whether the effect has physiological consequences for the animal, more direct measures of physiological stress and fitness consequences are required.

    “However, to analyse whether the effect has physiological consequences for the animal, more direct measures of physiological stress and fitness consequences are required [61,62].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [61] Clark, 2012, Relationship between behavior, adrenal activity, and environment in zoo-housed western lowland gorillas (Gorilla gorilla gorilla), Zoo Biol. source
    • cites [62] Palme, 2005, Measuring fecal steroids: Guidelines for practical application, Ann. N. Y. Acad. Sci. source

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

    Interpretationreasoning

    Publication bias in the visitor effect literature may be a result of the traditional focus of welfare science on identifying and managing negative welfare states in animals.

    “It should be noted that it is possible that this publication bias is a result of the traditional focus of welfare science on identifying and managing negative welfare states in animals”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisenone given

    There have been four main approaches to studying the visitor effect in zoos.

    “There have been, to date, four main approaches to studying the visitor effect in zoos.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    For some species and individuals, visitors can provide a source of stimulation or contribute to other positive experiences, providing opportunity for enhanced animal welfare and visitor experience.

    “Alternatively, for some species and individuals, it is possible that visitors can provide a source of stimulation or contribute to other positive experiences for animals, providing opportunity for enhanced animal welfare and visitor experience.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    For behaviours with no clear welfare implications, changes in time spent in response to visitor conditions can measure how visitors affect behaviour, but welfare consequences cannot be inferred from these changes alone.

    “For these behaviours, it may be useful to analyse any changes in time spent engaged in them in response to any changes in visitor conditions as a measure of how visitors can affect the behaviour of the animal, but welfare consequences cannot be inferred from these changes alone.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: A large proportion of an animal's behavioural repertoire is likely to consist of behaviours that have no clear implications for welfare, such as locomotion, vigilance and resting.

  • May combine two claims.

    Premisecitation

    Aggression can compromise welfare if it results in injury and has also been widely associated with physiological stress.

    “For example, aggression can compromise welfare if it results in injury [50] and has also been widely associated with physiological stress [47,51].”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [50] McCowan, 2008, Utility of social network analysis for primate behavioral management and well-being, Appl. Anim. Behav. Sci. source
    • cites [47] Hemsworth, 2015, Scientific assessment of animal welfare, N. Z. Vet. J. source
    • cites [51] Honess, 2006, Behavioural and physiological aspects of stress and aggression in nonhuman primates, Neurosci. Biobehav. Rev. source

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    Visitor experience and animal welfare are inextricably linked.

    “This makes visitor experience and animal welfare inextricably linked and highlights the importance of research in this area.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Experimental studies are necessary to determine the causality of visitor contact on animal behaviour and welfare.

    “These experimental studies are necessary to determine the causality of visitor contact on animal behaviour and welfare.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    A significant positive relationship was found between reproductive success in small felids and a husbandry style in which keepers spent more time talking to and interacting with the cats.

    “For example, a significant positive relationship was found between reproductive success in small felids and a husbandry style in which keepers spent more time talking to and interacting with the cats [39]”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [39] Mellen, 1991, Factors influencing reproductive success in small captive exotic felids (Felis spp.): A multiple regression analysis, Zoo Biol. source

  • May combine two claims.

    Premisecitation

    Faecal sampling offers the advantage of representing the average glucocorticoid metabolite concentration output over hours or days and represents pooled quantities of glucocorticoid secretion from the adrenal medulla, dampening pulsatile effects.

    “This technique offers the advantage of representing the average GC metabolite concentration output over hours or days [69] and, therefore, represents pooled quantities of GC secretion from the adrenal medulla (i.e., baseline plasma GC), dampening pulsatile effects [67,70].”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [69] Shepherdson, 2004, Cross-institutional assessment of stress responses in zoo animals using longitudinal monitoring of faecal corticoids and behaviour, Anim. Welf. source
    • cites [67] Keay, 2006, Fecal glucocorticoids and their metabolites as indicators of stress in various mammalian species: A literature review, J. Zoo Wildl. Med. source
    • cites [70] Carlstead, 2005, Relationships between patterns of Fecal corticoid excretion and behavior, reproduction, and environmental factors in captive black (Diceros bicornis) and white (Ceratotherium simum) rhinoceros, Zoo Biol. source

  • The quote only partly states this claim.

    Premisecitation

    Orangutans showed a preference to position themselves in front of the open window in a preference test with half of the window covered by a visual barrier.

    “It was found that the orangutans showed a preference to position themselves in front of the open window.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [16] Bloomfield, 2015, Effect of partial covering of the visitor viewing area window on positioning and orientation of zoo orangutans: A preference test, Zoo Biol. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    Increases in vigilance behaviour in zoo animals in response to increasing visitor numbers could alternatively be an anti-predator behaviour, which may result in fear and anxiety and consequently stress.

    “Alternatively, it could be an anti-predator behaviour, which may result in fear and anxiety and consequently stress.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    It is important to be cautious with interpretations of just one measure of welfare when investigating visitor effects and other environmental effects.

    “This, again, highlights the importance of being cautious with interpretations of just one measure of welfare when investigating visitor effects and other environmental effects.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Given that play behaviour is considered an indicator of positive animal welfare, it is possible that Diana monkeys were positively stimulated by visitors.

    “Given that play behaviour is considered an indicator of positive animal welfare [45], it is possible that this group of monkeys was also positively stimulated by visitors.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [45] Boissy, 2007, Assessment of positive emotions in animals to improve their welfare, Physiol. Behav. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Stoinski and colleagues studied four groups of gorillas in one zoo, examining how personality, sex and rearing history influenced their response to different crowd sizes.

    “They studied four groups of gorillas in one zoo, examining how a range of animal variables (including personality, sex and rearing history) influenced their response to different crowd sizes.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [131] Stoinski, 2012, Visitor effects on the behavior of captive western lowland gorillas: The importance of individual differences in examining welfare, Zoo Biol. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Broom suggests that the evolution of animals in their natural environment has resulted in each species having certain tolerable physiological limits to allow coping, as well as certain behavioural or psychological needs.

    “Broom [114] suggests that the evolution of animals in their natural environment has resulted in each species having certain tolerable physiological limits to allow coping, as well as certain behavioural or psychological needs.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [114] Broom, 2011, A History of Animal Welfare Science, Acta Biotheor. source

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    A neutral response to visitors may be far more widespread than the current literature implies.

    “Thus, it is possible that a neutral response to visitors is far more widespread than the current literature implies.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    An animal's response to humans will be influenced by life history characteristics of a species, and also by individual factors such as genetics, temperament and past experience with humans.

    “An animal’s response to humans will not only be influenced by life history characteristics of a species, but also by individual factors such as genetics (artificial and natural selection), temperament and past experience with humans [31].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [31] Price, E.O. (2002). Animal Domestication and Behavior, CAB International. source

  • May combine two claims.

    Premisecitation

    Red kangaroos spent a considerable proportion of their time engaged in visitor-directed vigilance (15-50%) compared to Kangaroo Island kangaroos (less than 2%) and consistently positioned themselves an average of 4 m further away from the visitor pathway.

    “The study found that red kangaroos (the species exposed to natural predation) spent a considerable proportion of their time engaged in visitor-directed vigilance (15–50%) compared to Kangaroo Island kangaroos (less than 2%) and consistently positioned themselves an average of 4 m further away from the visitor pathway compared to the island kangaroos.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [86] Sherwen, 2015, Impacts of visitor number on Kangaroos housed in free-range exhibits, Zoo Biol. source

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given

    If visitors are perceived by zoo animals as fear provoking or stressful stimuli, long term exposure to visitors could be a source of repetitive acute or chronic stress.

    “If visitors are perceived by zoo animals as fear provoking or stressful stimuli, long term exposure to visitors could be a source of repetitive acute or chronic stress.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationcitation

    The Gentoo penguins were not negatively affected by visitors, but instead were more active, which the authors interpret as a positive response.

    “These results indicate that these Gentoo penguins were not negatively affected by visitors, but instead were more active, which the authors interpret as a positive response”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Higher numbers of visitors were associated with greater behavioural diversity and increased pool use by Gentoo penguins.

    “The authors found that higher numbers of visitors were associated with greater behavioural diversity and increased pool use by penguins.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [110] Collins, 2016, The effect of the zoo setting on the behavioural diversity of captive gentoo penguins and the implications for their educational potential, J. Zoo Aquar. Res. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    One interpretation of the orangutan results is that the orangutans were attracted to viewing the visitors themselves, rather than the visitor viewing area.

    “one interpretation of these results is that the orangutans were attracted to viewing the visitors themselves, rather than the visitor viewing area.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationnone given

    Factors that may influence an animal's response to visitors include species evolutionary traits, individual animal traits and environmental features of the enclosure.

    “It is useful to consider the factors that may influence an animal’s response to visitors, such as species evolutionary traits, individual animal traits and environmental features of the enclosure.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Margulis and colleagues suggested that primates are more responsive to outside-enclosure disturbances in zoos in comparison to big cat species, and that this might reflect the different communication modes between the groups.

    “Margulis and colleagues [15] have also suggested that primates are more responsive to outside-enclosure disturbances in zoos in comparison to big cat species, and that this might reflect the different communication modes between the groups.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [15] Margulis, 2003, Effect of felid activity on zoo visitor interest, Zoo Biol. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Researchers have suggested that an animal may experience suffering if they are unable to adequately perform relevant activities.

    “Researchers have suggested that an animal may experience suffering if they are unable to adequately perform relevant activities [115].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [115] Toates, 1993, Who needs ‘behavioural needs’? Motivational aspects of the needs of animals, Appl. Anim. Behav. Sci. source

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationreasoning

    Because of publication bias, research may be more likely to be conducted and published in response to a perceived welfare concern.

    “Because of the publication bias mentioned above, research may be more likely to be conducted and published in response to a perceived welfare concern.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    It is possible that the behavioural differences between red kangaroos and Kangaroo Island kangaroos exist because the island kangaroos are naturally less fearful of humans compared to the red kangaroos that have experienced a strong evolutionary history of predation pressure.

    “It is possible that these behavioural differences exist because the island kangaroos are naturally less fearful of humans compared to the red kangaroos that have experienced a strong evolutionary history of predation pressure.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Two individuals of the same species housed in the same environment and provided with the same husbandry will not necessarily perceive the environment in the same way and may have very different welfare outcomes.

    “two individuals of the same species housed in the same environment and provided with the same husbandry will not necessarily perceive the environment in the same way and, as a result, may have very different welfare outcomes [124,125,126].”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [124] Bashaw, 2016, Does enrichment improve reptile welfare? Leopard geckos (Eublepharis macularius) respond to five types of environmental enrichment, Appl. Anim. Behav. Sci. source
    • cites [125] Hill, 2009, Measuring zoo animal welfare: Theory and practice, Zoo Biol. source
    • cites [126] Hosey, G., Melfi, V., and Pankhurst, S. (2009). Zoo Animals: Behaviour, Management and Welfare, Oxford University Press.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    The smaller number of studies demonstrating neutral effects of visitors compared to the number demonstrating negative effects is not representative of the situation in zoos.

    “it remains possible that the smaller number of studies demonstrating neutral effects of visitors compared to the number of studies demonstrating negative effects is not representative of the situation in zoos.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationreasoning

    Many of the changes in animal behaviours such as avoidance, hiding, aggression and reduction in play and activity are likely to have implications for visitor experience.

    “many of the changes in animal behaviours mentioned above such as avoidance, hiding, aggression and reduction in play and activity are likely to have implications for visitor experience.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based). May combine two claims.

    Interpretationreasoning

    This information will provide zoos with an evidence-based foundation to inform decision making on species selection in zoos, housing and husbandry approaches and better manage visitor engagement opportunities that will ultimately contribute to conservation success.

    “This information will provide zoos with an evidence-based foundation to inform decision making on species selection in zoos, housing and husbandry approaches and better manage visitor engagement opportunities that will ultimately contribute to conservation success.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Ross documented that polar bears showed a reduction in pacing and increased positive social play when given free access to their off-display areas, even though they rarely chose to enter this area.

    “Ross [139] documented that polar bears showed a reduction in pacing and increased positive social play when given free access to their off-display areas, even though they rarely chose to enter this area.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [139] Ross, 2006, Issues of choice and control in the behaviour of a pair of captive polar bears (Ursus maritimus), Behav. Process. source

  • May combine two claims.

    Premisecitation

    Hand-rearing can result in heightened fear, aggression and stress responses, as well as poor social and parenting skills.

    “These studies suggest that hand-rearing can result in heightened fear, aggression and stress responses, as well as poor social and parenting skills [135,137].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [135] Mellen, 1992, Effects of early rearing experience on subsequent adult sexual behavior using domestic cats (Felis catus) as a model for exotic small felids, Zoo Biol. source
    • cites [137] Rose, 2017, To pace or not to pace? A review of what abnormal repetitive behavior tells us about zoo animal management, J. Vet. Behav. source

  • May combine two claims.

    Premisecitation

    Anderson and colleagues manipulated the amount of retreat space available to African pygmy goats and Romanov sheep and found that aggression and escape attempts were lowest when they had access to the full retreat.

    “Anderson and colleagues [143] manipulated the amount of retreat space available to African pygmy goats and Romanov sheep and found that aggression and escape attempts were lowest when they had access to the full retreat.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [143] Anderson, 2002, Retreat Space and Human Visitor Density Moderate Undesirable Behavior in Petting Zoo Animals, J. Appl. Anim. Welf. Sci. source

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

    Interpretationnone given

    More studies conducted on a range of species and enclosures are likely to indicate emerging patterns that can assist in more clearly identifying animal and enclosure characteristics that facilitate either negative or positive human-animal interactions and allow zoos to manage accordingly.

    “More studies conducted on a range of species and enclosures are likely to indicate emerging patterns that can assist in more clearly identifying animal and enclosure characteristics that facilitate either negative or positive human–animal interactions and allow zoos to manage accordingly.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    Uncontrolled visitor feeding may impact animal health and behaviour.

    “Depending on the circumstances, uncontrolled visitor feeding may impact animal health and behaviour.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    In captive populations, natural selection is expressed through differential mortality and reproductive failure, with an inability to adapt to the close proximity of humans likely to be one of many selection pressures facing captive animals.

    “In captive populations, natural selection is expressed through differential mortality and reproductive failure [31], with an inability to adapt to the close proximity of humans likely to be one of many selection pressures facing captive animals.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [31] Price, E.O. (2002). Animal Domestication and Behavior, CAB International. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Emerging research has suggested that the presentation of animals in anthropogenic environments has a significant impact on public understanding and attitude towards the species' conservation status.

    “Emerging research on a related topic has suggested that the presentation of animals in anthropogenic environments has been shown to have a significant impact on public understanding and attitude towards the species’ conservation status.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Although not statistically significant, the researchers found sex differences in behavior, where males showed a trend towards higher rates of aggression when larger crowds were present.

    “Although not statistically significant, the researchers found sex differences in behavior, where males showed a trend towards higher rates of aggression when larger crowds were present.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [131] Stoinski, 2012, Visitor effects on the behavior of captive western lowland gorillas: The importance of individual differences in examining welfare, Zoo Biol. source

  • May combine two claims.

    Premisecitation

    Wielebnowski et al. found a negative correlation between enclosure height and faecal GC concentrations in clouded leopards and interpreted enclosure height as a measure of their ability to avoid contact with other animals and humans.

    “Wielebnowski et al. [40] found a negative correlation between enclosure height and faecal GC concentrations in clouded leopards and interpreted enclosure height as a measure of their ability to avoid contact with other animals and humans.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [40] Wielebnowski, 2002, Noninvasive assessment of adrenal activity associated with husbandry and behavioral factors in the North American clouded leopard population, Zoo Biol. source

  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationcitation

    The focus has been on studying species that are expected to respond negatively to visitors, but it is becoming equally pertinent to understand opportunities for positive human-animal relationships in zoos as some species may have positive experiences with visitors.

    “the focus has clearly been on studying species that are expected to respond negatively to visitors, but it is becoming equally as pertinent to understand opportunities for positive human–animal relationships in zoos [32] as some species may have positive experiences with visitors”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [32] Hosey, G., and Melfi, V. (2018). Zoo animals. Anthrozoology: Human-Animal Interactions in Domesticated and Wild Animals, Oxford University Press. source

  • May combine two claims.

    Premisecitation

    Baird and colleagues found that a large amount of handling associated with education programs increased pacing behaviour in armadillos and increased faecal GC concentration in armadillos, hedgehogs and hawks.

    “Baird and colleagues [151] found that a large amount of handling associated with education programs increased pacing behaviour in armadillos and increased faecal GC concentration in armadillos, hedgehogs and hawks.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [151] Baird, 2016, Program animal welfare: Using behavioral and physiological measures to assess the well-being of animals used for education programs in zoos, Appl. Anim. Behav. Sci. source

  • May combine two claims.

    Premisecitation

    Owen found that pandas had lower cortisol levels and fewer signs of behavioural agitation when given the choice of where to spend their time.

    “Owen [140] found that pandas had lower cortisol levels and fewer signs of behavioural agitation when given the choice of where to spend their time.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [140] Owen, 2004, Monitoring stress in captive giant pandas (Ailuropoda melanoleuca): Behavioral and hormonal responses to ambient noise, Zoo Biol. source

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Interpretationreasoning

    Visitors feeding animals may result in zoo animals associating visitors with a positive experience, but it may also result in mismanagement of nutrition for certain animals, resulting in health problems.

    “visitors feeding animals may result in zoo animals associating visitors with a positive experience, but it may also result in mismanagement of nutrition for certain animals, resulting in health problems.”
    Quote in the paperNot a substantial claim
95 of 95

  • The paper relies on this without support.

    An animal's welfare is highly dependent on how various individual animal factors interact with environmental features.

    “Research has shown that an animal’s welfare is highly dependent on how various individual animal factors (e.g., species traits, genetics, temperament and previous experience) interact with environmental features (e.g., social grouping, enclosure design and sensory environment).”

  • The paper relies on this without support.

    Visitors are a prominent feature of the zoo animal's environment, with frequent, and at times close and intense, interactions.

    “Visitors are a prominent feature of the zoo animal’s environment, particularly the frequent, and at times close and intense, interactions.”

  • The paper relies on this without support.

    The presence of visitors is a universal characteristic of the zoo environment.

    “The presence of visitors is a universal characteristic of the zoo environment.”

  • The paper relies on this without support.

    A large proportion of an animal's behavioural repertoire is likely to consist of behaviours that have no clear implications for welfare, such as locomotion, vigilance and resting.

    “A large proportion of an animal’s behavioural repertoire is likely to consist of behaviours that have no clear implications for welfare, such as locomotion, vigilance and resting.”

  • The paper relies on this without support.

    Zoo animals have undergone some level of natural selection in their captive environment, but at an industry level they have not been purposefully bred for traits associated with adaptation to humans.

    “Zoo animals have no doubt undergone some level of ‘natural selection’ in their captive environment, however, at an industry-level, they have not been purposefully bred for traits associated with adaptation to humans.”

  • The paper relies on this without support.

    Zoo animals are regularly exposed to both familiar and unfamiliar humans in their environment.

    “Nonetheless, it is clear that zoo animals are regularly exposed to both familiar and unfamiliar humans in their environment, and, as such, it is possible that this human interaction will have an impact on their welfare.”
6 of 6

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • The novelty of covering the main window and associated changes such as illumination may have stimulated inspection by the penguins.

    “However, it is important to note that vigilance is not always an indicator of fear and may indicate curiosity and since the main window was randomly covered for five 1-day periods over 2 weeks, the novelty of covering the window and the associated changes such as illumination in the area, may have stimulated inspection [1,51].”

    From Effect of Covering a Visitor Viewing Area Window on the Behaviour of Zoo-Housed Little Penguins (Eudyptula minor) (2020) · cites this paper as [1]

    Section 2.1 (Metrics Studied; page unavailable) says increased vigilance can reflect interest rather than fear, supporting the citing sentence’s general caution. Section 2.2 describes blocking visitor access to little penguins, but our copy does not say that the novelty of covering a window or changes in illumination stimulated their inspection. (LLM, conf=0.86)

    Experimental — accuracy not yet measured

  • Decades of research indicate that the effect of zoo visitors can be negative, neutral, or positive in terms of animal behavior and welfare.

    “Decades of research indicate that the effect of zoo visitors can be negative, neutral, or positive in terms of animal behavior and welfare (Hosey & Melfi, 2014;Sherwen & Hemsworth, 2019).”

    From Continuing challenges of elephant captivity: the captive environment, health issues, and welfare implications (2024) · cites this paper as Sherwen & Hemsworth, 2019

  • Species-specific differences, nature of visitor interactions, enclosure design, and individual animal temperament may contribute to variation in zoo animal responses.

    “Species-specific differences, the nature of the visitor interactions, enclosure design, and individual animal temperament may contribute to the variation in zoo animal responses (Sherwen & Hemsworth, 2019).”

    From Continuing challenges of elephant captivity: the captive environment, health issues, and welfare implications (2024) · cites this paper as Sherwen & Hemsworth, 2019

  • Vigilance is not always an indicator of fear and may indicate curiosity.

    “However, it is important to note that vigilance is not always an indicator of fear and may indicate curiosity and since the main window was randomly covered for five 1-day periods over 2 weeks, the novelty of covering the window and the associated changes such as illumination in the area, may have stimulated inspection [1,51].”

    From Effect of Covering a Visitor Viewing Area Window on the Behaviour of Zoo-Housed Little Penguins (Eudyptula minor) (2020) · cites this paper as [1]

  • Research needs expanding to encompass species specificity within collections due to multiple study focusses surrounding charismatic species, like primates.

    “Sherwen & Hemsworth, (2019) identified that research needs expanding to encompass species specificity within collections due to multiple study focusses surrounding charismatic species, like primates.”

    From An Investigation into the Perception and Prevalence of Mixed-Species Exhibits in Zoos and Aquaria (2022) · cites this paper as Sherwen & Hemsworth, (2019)

Cites

Flagged first, then by citations

Research works printed but not linked: 3

  1. Hediger, H. (1970). Man and Animal in the Zoo, Routledge Kegan Paul.
  2. Mellor, D.J., Patterson-Kane, E., and Stafford, K.J. (2009). The Sciences of Animal Welfare, Wiley-Blackwell.
  3. Skynner, 2004, The effect of visitors on the self-injurious behaviour of a male pileated gibbon (Hylobates pileatus), Zool. Gart., 74, 38

Cited by

Sorted by citations

Related

Authors
Sherwen, S. L., & Hemsworth, P. H.
Affiliations
The University of Melbourne (AU)
Corresponding author
Sherwen, Sally L.
ORCID
Venue
Animals
Publisher
MDPI AG
Published
2019-06-17
Volume
9
Issue
6
Pages
366
ISSN
2076-2615 (ISSN-L)
DOI
10.3390/ani9060366
PMC
PMC6617010
OpenAlex
W2951256062
Semantic Scholar
c5fae4f6567e8e45dcc643d578ed579cbbee377d
Cited by
267
References
166
Citations by year
2026: 23 · 2025: 37 · 2024: 36 · 2023: 46 · 2022: 45 · 2021: 53 · 2020: 22 · 2019: 4
FWCI
6.57
Type
journal article
Language
en
Open access
Licence
Locations
  • Animals (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Minerva Access (University of Melbourne) (submittedVersion, cc-by)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Topics
  • Health Sciences › Veterinary › Small Animals › Animal Behavior and Welfare Studies
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Human-Animal Interaction Studies
  • Social Sciences › Psychology › Social Psychology › Animal and Plant Science Education
Keywords
zoo animal welfare, visitor effects, zoo animals, animal behavior, enclosure design, sensory environment, species differences, positive reinforcement, negative reinforcement

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-27.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-27.

Cited sources are checked by gpt-6-sol.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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